The detach_adapter callback has been deprecated for quite some time and has no
user left. Keeping it alive blocks other cleanups, so remove it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>